Synthesis and characterization of LiNi0.5Co0.2Mn0.3O2 cathode material prepared by a novel hydrothermal process

A novel hydrothermal process followed by heat treatment was used for the preparation of the layered LiNi0.5Co0.2Mn0.3O2 cathode materials for lithium ion batteries. The lithiated metal oxide precursor obtained from the hydrothermal process had a homogeneous distribution of metals and a weak crystallinity. The layered LiNi0.5Co0.2Mn0.3O2 powders were obtained by the post-heat treatment of the lithiated metal oxide. The materials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), inductively coupled plasma (ICP), atomic absorption spectroscopy (AAS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge testing. The cathode material with hexagonal α-NaFeO2 structure, low cation mixing, appropriate crystallinity and homogeneous spherical particles was obtained. The results indicated that the initial discharge capacities of the cathode material were 150 mAh g−1, 165.7 mAh g−1 and 184.8 mAh g−1 at the discharge rate of 0.5 C (100 mA g−1) with the cut-off voltage range of 3.0–4.3 V, 2.8–4.4 V and 2.5–4.5 V, respectively, and it retained 97.6%, 99.4% and 99.2% of the initial capacity after 50 cycles. It indicated that the novel hydrothermal lithiation followed by post-heat treatment is a promising route for the synthesis of LiNi0.5Co0.2Mn0.3O2 cathode material with improved properties.